Elevated soluble syndecan-1 levels in neuromyelitis optica are associated with disease severity

Syndecan-1 (SDC-1) is a transmembrane member that has a profound influence on the resolution of inflammation. Soluble syndecan-1 (sSDC-1) levels have been shown to increase in many inflammatory diseases. However, it remains unknown whether sSDC-1 concentration is elevated in neuromyelitis optica (NMO) and multiple sclerosis (MS) patients. The aims of this pilot study were to investigate the relationship between sSDC-1 and disease severity in NMO and MS and whether sSDC-1 has potential as an effective marker for disease severity. We measured sSDC-1 concentrations by using an enzyme-linked immunosorbent assay (ELISA). NMO patients had significantly higher CSF sSDC-1 levels than MS patients or controls. We also found a positive correlation between the increased CSF sSDC-1 levels and increased severity in NMO disease, but not in MS. In NMO, CSF sSDC-1 concentrations were positively correlated with CSF interleukin (IL)-6, IL-8 and IL-17. Overall, we showed levels of CSF sSDC-1 were higher in NMO patients and had a positive relationship with disease severity of NMO but not with MS. CSF sSDC-1 may be an effective marker of NMO disease severity.